Problem
Despite the fact that Vitacress produces several different types of vegetables, the process used to wash and package the vegetables is very similar. When the trucks arrive at the factory with vegetable leaves, the first step is to weigh them and to transfer them to a machine that washes and undertakes the hygiene of the leaves. There is capacity to weigh and transfer 5 tons of dirty leaves per hour. Furthermore, the machine that washes and undertakes the hygiene of the vegetables has capacity to handle 3 tons of dirty leaves per hour. This cleaning operation involves a residual loss of weight, but this loss can be neglected for this analysis. After washing, the leaves move into a drying machine, which has capacity to dry 3 tons of vegetables per hour. Once dried the leaves move into an optical quality control machine which can inspect 2.5 tons of leaves per hour. After this inspection, an average of 20% of the leaves are rejected for lack of quality. The remaining 80% follow the process to be packaged in plastic bags. The factory has two packaging machines.
Each machine has capacity to package 4600 individual bags (of 250 g each) per hour. Afterwards, the individual bags are put inside carton boxes (each box with 10 individual bags) ready for delivery. The company has 6 employees dedicated to this last activity. Each employee needs 20 seconds to complete a box with 10 individual bags. Assume that the factory works 8 hours per day.
I. Assuming that this is a stable process and that there are no other restrictions regarding the capacity of this process, calculate the maximum daily capacity of the entire process, identify the bottleneck(s) in this process and estimate the average utilization rate for each activity. Present all the necessary calculations to justify your answers. Assume maximum possible throughput.
II. Identify three factors that may affect the average utilization rate of the activities.